DOI: 10.5194/cp-10-1567-2014
Scopus记录号: 2-s2.0-84908051938
论文题名: Deglacial ice sheet meltdown: Orbital pacemaking and CO<inf>2</inf> effects
作者: Heinemann M. ; Timmermann A. ; Elison Timm O. ; Saito F. ; Abe-Ouchi A.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2014
卷: 10, 期: 4 起始页码: 1567
结束页码: 1579
语种: 英语
Scopus关键词: carbon dioxide
; climate modeling
; deglaciation
; glacial environment
; ice sheet
; Northern Hemisphere
; paleoclimate
; proxy climate record
英文摘要: One hundred thousand years of ice sheet buildup came to a rapid end ∼25-10 thousand years before present (ka BP), when ice sheets receded quickly and multi-proxy reconstructed global mean surface temperatures rose by ∼3-5 °C. It still remains unresolved whether insolation changes due to variations of earth's tilt and orbit were sufficient to terminate glacial conditions. Using a coupled three-dimensional climate-ice sheet model, we simulate the climate and Northern Hemisphere ice sheet evolution from 78 ka BP to 0 ka BP in good agreement with sea level and ice topography reconstructions. Based on this simulation and a series of deglacial sensitivity experiments with individually varying orbital parameters and prescribed CO2 , we find that enhanced calving led to a slowdown of ice sheet growth as early as ∼8 ka prior to the Last Glacial Maximum (LGM). The glacial termination was then initiated by enhanced ablation due to increasing obliquity and precession, in agreement with the Milankovitch theory. However, our results also support the notion that the ∼100 ppmv rise of atmospheric CO 2 after ∼18 ka BP was a key contributor to the deglaciation. Without it, the present-day ice volume would be comparable to that of the LGM and global mean temperatures would be about 3 °C lower than today. We further demonstrate that neither orbital forcing nor rising CO2 concentrations alone were sufficient to complete the deglaciation. © Author(s) 2014. 资助项目: NSF, National Stroke Foundation
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49233
Appears in Collections: 气候变化与战略
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Recommended Citation:
Heinemann M.,Timmermann A.,Elison Timm O.,et al. Deglacial ice sheet meltdown: Orbital pacemaking and CO<inf>2</inf> effects[J]. Climate of the Past,2014-01-01,10(4)